Method of anchoring an  intraocular lens assembly

ABSTRACT

An intraocular lens assembly for implantation in the posterior chamber of an eye has anchor portions with teeth rigid enough to penetrate the scleral wall of an eye. A method for implanting the lens includes the steps of: introducing the first haptic portion with a first anchor portion that includes a plurality of teeth projecting therefrom, into the posterior chamber of the eye until said teeth are anchored in the scleral wall at a desired location; and moving a second haptic portion with a plurality of teeth projecting therefrom, until said teeth are anchored in the scleral wall on the opposite side of the lens from the first anchor portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. patentapplication Ser. No. 12/906,774, filed on Oct. 18, 2010, which is aContinuation Application of U.S. patent application Ser. No. 11/734,180,filed on Apr. 11, 2007, which issued on Dec. 21, 2010 as U.S. Pat. No.7,854,764, which was a Continuation Application of U.S. patentapplication Ser. No. 10/487,005, filed on Feb. 19, 2004, which was anational stage application of PCT/IL02/00693 filed Aug. 21, 2002,claiming priority to IL 145015 filed Aug. 21, 2001, all of which areincorporated herein by reference in their entirety.

FIELD OF THE INVENTION

This invention relates to intraocular lenses, and in particular, toaccommodating intraocular lenses capable of focusing on objects locatedat various distances therefrom.

BACKGROUND OF THE INVENTION

The natural lens of a human eye is a transparent crystalline body, whichis contained within a capsular bag located behind the iris and in frontof the vitreous cavity in a region known as the posterior chamber. Thecapsular bag is attached on all sides by fibers, called zonules, to amuscular ciliary body. At its rear, the vitreous cavity, which is filledwith a gel, further includes the retina, on which light rays passingthrough the lens are focused. Contraction and relaxation of the ciliarybodies changes the shape of the bag and of the natural lens therein,thereby enabling the eye to focus light rays on the retina originatingfrom objects at various distances.

Cataracts occur when the natural lens of the eye or of its surroundingtransparent membrane becomes clouded and obstructs the passage of lightresulting in various degrees of blindness. To correct this condition ina patient, a surgical procedure is known to be performed in which theclouded natural lens, or cataract, is extracted and replaced by anartificial intraocular lens. During cataract surgery, the anteriorportion of the capsular bag is removed along with the cataract, and theposterior portion of the capsular bag, called the posterior capsule, issometimes left intact to serve as a support site for implanting theintraocular lens. Such lenses, however, have the drawback that they havea fixed refractive power and are therefore unable to change their focus.

Various types of intraocular lenses having the capability of alteringtheir refractive power have been suggested in an effort to duplicate theperformance of the natural lens within the eye. Such accommodatingintraocular lenses, as they are known in the art, have a variety ofdesigns directed to enable the patient to focus on, and thereby clearlysee, objects located at a plurality of distances. Examples may be foundin such publications as U.S. Pat. No. 4,254,509; U.S. Pat. No.4,932,966; U.S. Pat. No. 6,299,641; and U.S. Pat. No. 6,406,494.

U.S. Pat. No. 5,489,302 discloses an accommodating intraocular lens forimplantation in the posterior chamber of the eye. This lens comprises ashort tubular rigid frame and transparent and resilient membraneattached thereto at its bases. The frame and the membranes confine asealed space filled with a gas. The frame includes flexible regionsattached via haptics to the posterior capsule. Upon stretching of thecapsule by the eye's ciliary muscles, the flexible regions are pulledapart, thereby increasing the volume and decreasing the pressure withinthe sealed space. This changes the curvature of the membranes andaccordingly, the refractive power of the lens.

U.S. Pat. No. 6,117,171 discloses an accommodating intraocular lenswhich is contained inside an encapsulating rigid shell so as to make itsubstantially insensitive to changes in the intraocular environment. Thelens is adapted to be implanted within the posterior capsule andcomprises a flexible transparent membrane, which divides the interior ofthe intraocular lens into separate front and rear spaces, each filledwith a fluid having a different refractive index. The periphery of therear space is attached to haptics, which are in turn attached to theposterior capsule. Upon stretching of the capsule by the eye's ciliarymuscles, the haptics and hence this periphery is twisted apart toincrease the volume of rear space and changes the pressure differencebetween the spaces. As a result, the curvature of the membrane andaccordingly, the refractive power of the lens changes.

BRIEF SUMMARY OF THE INVENTION

The present invention suggests an accommodating lens assembly having anoptical axis and being adapted to be implanted in a posterior chamber ofan eye having a capsular unit located therein. The assembly comprises arigid haptics element adapted to secure the assembly within saidposterior chamber outside the capsular unit, the element beingtransparent at least in a region around the axis. The assembly furthercomprises a resilient body adapted to operate as a lens with a radius ofcurvature, when pressed up against the region of the rigid element by anaxial force applied thereto by the capsular unit, whereby a change insaid force causes a change in the radius of curvature.

The term “capsular unit”, as it is used in the present description andclaims, refers to the posterior capsule, the zonules, and the ciliarybody, which are interconnected and act in unison, forming in accordancewith the present invention, a kind of cable whose varying tensionprovides the axial force applied to and utilized by the lens assembly ofthe present invention to achieve accommodation.

The assembly of the present invention is directed to substitute for anatural lens after its removal from the eye, not only by enabling theeye to see after implantation of the assembly, but also by enabling itto accommodate and thereby bring into focus objects located at acontinuum of distances. In order to achieve the latter, the assembly isdesigned to be fixed in the posterior chamber, with the resilient bodyaxially abutting the posterior capsule. The resilient body may beattached to the haptic element or may simply be held in place up againstthe element by the tension of the capsular unit.

The lens assembly of the present invention utilizes the naturalcompression and relaxation of the capsular unit to impart an axial forceon the resilient body in order to cause it to act as a lens whose radiusof curvature, and therefore the refractive power it provides, variesdepending on the magnitude of the force. In this way, the lens assemblycooperates with the natural operation of the eye to accommodate andenable the eye to clearly see objects at different distances.

The haptics element of the assembly according to the present inventionmay adopt any of a variety of designs known in the art, e.g. it may becurved or it may be in the form of a plate, which spans a planeessentially perpendicular to the optical axis of the assembly. Inaddition to the region, the haptics element may be completelytransparent. The region of the element may be in the form of atransparent component, such as a clear panel or another lens which mayhave such a curvature and index of refraction as to enhance theaccommodating capability of the lens assembly.

The haptics element may have a hollow space formed in its transparentregion. This hollow space is adapted to allow the resilient body tobulge through the space in response to said force. This enables the lensassembly to provide a range of refractive power (i.e. the accommodatingcapability) depending on the bulge's radius of curvature, which isdetermined and may be varied by the magnitude of the force applied bythe capsular unit.

The haptics element of the lens assembly of the present invention isadapted to securely fix the assembly in front of the capsular unit inthe posterior chamber of the eye. It is essential that the hapticselement maintain a substantially immovable position. To this end, thehaptics element is preferably adapted to be fixed to the scleral wall ofthe eye in two or more places in the regions between the iris and theciliary body. To achieve the latter, the haptics element preferablycomprises anchoring means, such as in the form of teeth. One example ofsuch means is described in co-pending Israel patent application no.141529.

Implantation of the lens assembly in accordance with the presentinvention may be achieved using equipment and techniques that areconventional and well known in the art. However, in order to facilitatethe implantation and anchoring of the assembly in the eye, the hapticselement of the assembly of the present invention preferably alsoincludes at least one extendible member at its periphery. For example,the haptics element in the form of a plate discussed above may have atelescoping end which is only extended after the assembly has beeninserted into the eye and has been positioned at the anchoring site.This extendible member may also be provided with anchoring meansattached thereto. The extendible member serves to keep the assemblysmall enough to insert into the eye until its securing is desired. Theextendible member, such as the telescoping end, may be passive or may bespring biased being compressed to enable implantation and released tomaintain anchoring by a resisting force.

The haptics element of the lens assembly in accordance with the presentinvention may be made of a variety of possible rigid materials suitablefor invasive medical use and known in the art to be used in theformation of haptics.

The resilient body of the accommodating lens assembly in accordance withthe present invention may be made of any suitable deformable material,such as silicone or hydrogel, having an index of refraction differentfrom the gel within the eye. The resilient body must not necessarily bemade of a single component or material. For example, the body may be inthe form of a sac filled with a fluid or gel. However, in the case ofsuch a sac, for example, it is essential the periphery of the body bemade with a unitary material so that the fluctuating internal pressureof the eye does not affect the sac in an anisotropic manner, which wouldunpredictably affect the vision provided by the assembly.

The resilient body of the accommodating lens assembly in accordance withthe present invention may have a variety of shapes so long as the shapehas or is able to achieve a radius of curvature and thereby perform as alens. For example, in the case when the haptics element is curved andsolid (i.e. is devoid of a hollow space in said region), the resilientbody may have such shapes as a sphere which, when pressed against itshaptics element, takes on the shape of a double convex lens. Also, ifthe haptics element is flat like a plate, for example, the planar sideof a hemispherical resilient body may be pressed up against it to act asa plano-convex lens. As another example, if the haptics element is flatand comprises a hollow space, such as an aperture or a cavity, theresilient body having a bi-planar shape, such as that of a solidcircular disc, may be pressed up against the element since the forceapplied by the capsular unit will cause it to bulge into the aperture orcavity and attain, thereby, a radius of curvature.

The accommodating lens assembly in accordance with the present inventionmay further comprise a rigid piston member, which sandwiches theresilient body between it and the haptics element, and which is designedto be pushed by the force and, in response, to cause the resilient bodyto take on a desired curved shape. The piston member is transparent atleast in a region around the axis and is movable along the axis withrespect to the element. One or both of the haptics element and thepiston member have a hollow space in their transparent region to allowthe resilient body to bulge through the space in response to the force.

The hollow spaces formed in the haptics element and/or the piston memberin preferred embodiments of the lens assembly in accordance with thepresent invention, may have various designs such as circular blind orthrough holes. Preferable, these spaces are large enough that theirperiphery is far from the optical axis so as not to substantially affectlight passing thereabout by causing diffraction and other such undesiredoptical effects. Also, in order to minimize such optical disturbances,if a hollow space is formed within the piston member, the hapticselement may be devoid of such a space and vice versa.

The piston member of the accommodating lens assembly of the presentinvention may be made of any of a variety of rigid biocompatiblematerials. The piston member may also have any of a variety of designs,such as a plano-convex design with the convexly curved side abutting thecapsular unit so as to contribute to the range of refractive power whichmay be achieve by the assembly. Clearly, in the latter case, thetransparent region of the piston member, like the resilient body, musthave an index of refraction different from the natural gel surroundingthe assembly when implanted in the eye. The radius of curvature and theindex of refraction of the piston member may be adjusted and chosen innumerous ways to arrive at lens assemblies having various ranges ofrefractive power and degrees of sensitivity to the force applied by thecapsular unit.

The advantages provided by the accommodating lens assembly of thepresent invention abound; particularly because of it is designed to bepositioned in the eye completely outside of the posterior capsule. Oneadvantage, for example, is that the lens assembly does not undesirablystretch and consequently harm the capsule. Also, the lens assembly doesnot need to conform to the size or shape of the capsule, and istherefore free to take on a larger variety of designs. Furthermore, thecapsule is sometimes damaged during the surgery to remove the naturallens, but the lens assembly of the present invention does not requirethat the capsule be completely intact in the form of a bag but merelythat it remain reliably connected as part of the capsular unit. Anotheradvantage arising from the lens assembly being positioned outside of theposterior capsule is that it remains unaffected by the permanent andunpredictable constriction that the capsule inevitably undergoes due toscarring following the surgery for removal of the natural lens.

In addition to the above, the lens assembly of the present inventionoffers advantages such as a simple and inexpensive construction. Thelens assembly of the present invention also provides the ability toaccommodate within a vast range of refractive power, including the fullrange provided by the natural eye. Also, the lens assembly providesmeans for varying its sensitivity in response to the force applied bythe capsular unit.

The foregoing has outlined rather broadly the features and technicaladvantages of the present invention in order that the detaileddescription of the invention that follows may be better understood.Additional features and advantages of the invention will be describedhereinafter which form the subject of the claims of the invention. Itshould be appreciated by those skilled in the art that the conceptionand specific embodiment disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present invention. It should also be realized by thoseskilled in the art that such equivalent constructions do not depart fromthe spirit and scope of the invention as set forth in the appendedclaims. The novel features which are believed to be characteristic ofthe invention, both as to its organization and method of operation,together with further objects and advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. It is to be expressly understood, however, thateach of the figures is provided for the purpose of illustration anddescription only and is not intended as a definition of the limits ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carriedout in practice, a preferred embodiment will now be described, by way ofnon-limiting example only, with reference to the accompanying drawings,in which:

FIG. 1A is a plan view of an accommodating lens assembly in accordancewith the present invention;

FIG. 1B is a side view of the accommodating lens assembly shown in FIG.1A;

FIG. 2A shows the accommodating lens assembly of FIGS. 1A and 1B asimplanted in an eye;

FIG. 2B shows the accommodating lens assembly of FIGS. 1A and 1B inoperation after it has been implanted in an eye as in FIG. 2A;

FIG. 3A is a plan view of another embodiment of an accommodating lensassembly in accordance with the present invention;

FIG. 3B is a side view of the accommodating lens assembly shown in FIG.3A;

FIG. 4A shows the accommodating lens assembly of FIGS. 3A and 3B asimplanted in an eye;

FIG. 4B shows the accommodating lens assembly of FIGS. 3A and 3B inoperation after it has been implanted in an eye as in FIG. 4A;

FIG. 5A shows yet another embodiment of an accommodating lens assemblyin accordance with the present invention as implanted in the eye;

FIG. 5B shows the accommodating lens assembly of FIG. 5A in operation inthe eye.

DETAILED DESCRIPTION OF THE INVENTION

The subsequent description and figures refer to different examples of anaccommodating lens assembly of the present invention and its functionalposition as implanted in a human eye E. As shown in FIGS. 2A, 2B, 4A,4B, 5A, and 5B, the eye E, which is filled with natural gel (not shown)having an index of refraction of about 1.3, comprises a scleral wall S,an iris, and a retina R (not shown). The eye E further includes aciliary body CB, from which extend zonules Z connected to a posteriorcapsule PC. These last three parts of the eye E constitute the capsularunit 1.

One example of an accommodating lens assembly in accordance with thepresent invention adapted for implantation within the eye E is shown inFIG. 1A in plan view and in FIG. 1B from a side view. The accommodatinglens assembly 2 has an optical axis A-A and comprises a rigid hapticsplate 4 having a first lens 6 made of a rigid material having an indexof refraction higher than that of water. The plate 4 further includes atelescoping haptics member 8, which is slidably biased in grooves 8 a soas to be extendible in a plane perpendicular to the optical axis A-A.The plate 4 and the telescoping member 8 have teeth 9 projectingtherefrom for anchoring the first lens assembly 2 within the eye E.

The lens assembly 2 further comprises a silicone ball 10 attached to theplate 4 so as to be located on the axis A-A. The silicone ball 10 alsohas an index of refraction higher than that of water.

As is shown in FIGS. 2A and 2B, the haptics plate 4 of the assembly 2 isanchored, using the teeth 9, to the eye's scleral wall S at twolocations between the ciliary body CB and the iris I. The anchoring isdone by first inserting the teeth 9 on the plate 4 to the desired pointin the scleral wall S, and then extending the telescoping member 8 untilits teeth 9 enter the opposing side of the scleral wall S. The siliconeball 10 directly contacts the capsular unit 1, which is stretched aroundthe ball 10 and transforms it into a second plano-convex lens 10′ asshown in FIG. 2A with a radius of curvature R1.

In operation, upon contraction and relaxation by muscles of the ciliarybody CB, tension in the capsular unit 1 will change and a variable forceproportional to the tension will be applied to the silicone ball 10along axis A-A. FIG. 2B shows an increase in tension in the capsularunit 1 compared to FIG. 2A upon relaxation of the ciliary body CB. Theincrease in tension applies a forward force along the axis in thedirection of the iris I. This force causes the lens 10′ to furtherdeform and increase its radius of curvature from R1 to R2. This increasein radius will enable the eye E to focus on far objects by adjusting theassembly's focal plane until it resides on the retina. Clearly, thereverse may be done in which the ciliary body contracts, reducing theradius to focus on objects at near distances from the eye E.

Another example of an accommodating lens assembly 22 for implantationwithin a human eye E in accordance with the present invention is shownin a preferred embodiment in FIG. 3A in plan view and in FIG. 3B from aside view.

The accommodating lens assembly 22 has an optical axis B-B and comprisesa rigid haptics plate 24, similar to that included in the lens assembly2, and having a circular aperture 26. The plate 24 further includes atelescoping member 28, which is slidably biased in grooves 28 a so as tobe extendible. The plate 24 and the telescoping member 28 have teeth 29projecting therefrom for anchoring the lens assembly 22 within the eye.The plate further includes a hollow, central cylindrical tube portion Textending around axis B-B. The tube portion T is concentric with theaperture 26 but has about double the diameter.

The accommodating lens assembly 22 further comprises a silicone disc 30received within the tube portion T so as to occupy only a part of itsaxial dimension. The disc 30 has an index of refraction higher than thatof water.

The lens assembly 22 also includes a rigid, plano convex lens 31 havinga diameter slightly smaller than that of the tube portion T but greaterthan that of the aperture 26. The lens 31, which is designed to functionlike a piston by transferring an applied force to the disc 30, isreceived within the tube portion T to fill the space left unoccupied bythe disc 30 and to press, with its planar face, the disc 30 up againstthe plate 24. The plano-convex lens 31 has a fixed radius of curvatureand an index of refraction higher than that of water.

FIGS. 4A and 4B show the haptics plate 24 of the assembly 22 anchored,using the teeth 29, to the eye's scleral wall S at two locations, eachbeing between the ciliary body CB and the iris I. The silicone disc 30is sandwiched between the haptics plate 24 and the lens 31, whichdirectly contacts the capsular unit 1 with its convex side.

In operation, upon contraction and relaxation by muscles of the ciliarybody CB, tension in the capsular unit 1 will change and apply a force tothe lens 31 along axis B-B. FIG. 4B shows an increase in tension in thecapsular unit 1 compared to FIG. 4A, which occurs upon relaxation of theciliary body CB. This increase in tension applies a forward force on thelens 31 along the axis in the direction of the iris I. The applied forcepushes the lens 31, which functions like a piston and presses, in turn,on the silicone disc 30, causing it to protrude from the aperture 26 inthe form of a bulge 35 having a radius of curvature depending on theforce. The bulge 35 serves to add to the refractive power afforded bythe convex curvature of lens 31. In this way, using the lens assembly22, the eye E is given the ability to focus on nearer objects bychanging the magnitude of the applied force and hence the radius of thebulge 35 until the object is focused on the retina R.

Yet another example of a lens assembly 42 in accordance with the presentinvention for implantation into the eye E is shown in a preferredembodiment in FIGS. 5A and 5B. The lens assembly 42 is similar to thelens assembly 22 in that it comprises a haptics plate 44 with anaperture which is occupied by a rigid lens 46, similarly to lens 6 inFIG. 1A. Furthermore, the lens assembly 42 comprises a piston member 51.However, the piston member 51 has a cylindrical cavity 52 formedtherein, into the silicone disc 50 is adapted to bulge. The member 51 isadapted transfer an axial force applied by the capsular unit 1 tosilicone disc 50 sandwiched between the member 51 and the plate 44. Inthis way, the piston member 51 is similar to plano-convex lens 31 showne.g. in FIG. 4A, but differs in that it does not have the additionalability to operate as a lens.

In operation, the piston member 51 of the lens assembly 42 transfers theaxial force, created thereon by changes of tension in the capsular unit1, to the silicone disc 50, causing it to faun a bulge 54, whichprotrudes back into the cavity 52. The bulge 54 has a radius ofcurvature whose value varies depending on the magnitude of the force. Asin the previously described embodiment, the bulge 54 serves to providethe assembly 42 with a refractive power, whose magnitude can be variedby the force applied by the capsular unit 1 and controlled by thecontraction and relaxation of muscles in the eye's ciliary body CB.

Although the present invention and its advantages have been described indetail, it should be understood that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of the invention as defined by the appended claims. For example,while implantation of the lens assembly in humans is described, theassembly may clearly also be applicable to other animals. Clearly, anyand all possible permutations and/or combinations of different featuresas described above are within the scope of the present invention.

Moreover, the scope of the present application is not intended to belimited to the particular embodiments of the process, machine,manufacture, composition of matter, means, methods and steps describedin the specification. As one of ordinary skill in the art will readilyappreciate from the disclosure of the present invention, processes,machines, manufacture, compositions of matter, means, methods, or steps,presently existing or later to be developed that perform substantiallythe same function or achieve substantially the same result as thecorresponding embodiments described herein may be utilized according tothe present invention. Accordingly, the appended claims are intended toinclude within their scope such processes, machines, manufacture,compositions of matter, means, methods, or steps.

1-18. (canceled)
 19. A method of anchoring an intraocular lens assemblyin the posterior chamber of an eye, the lens assembly having an opticalaxis that corresponds with the visual axis of a human eye, the posteriorchamber including a ciliary sulcus, the assembly comprising asubstantially rigid haptics element comprising first and second hapticportions with outermost portions, comprising first and second anchorportions with a plurality of teeth rigid enough to penetrate the scleralwall, which, when the teeth are anchored in the scleral wall, define aplane that intersects the visual axis of the eye, said haptics elementsecuring said intraocular lens assembly within the posterior chamber,and a lens structure that includes at least a lens body located at leastpartially along the visual axis when the lens assembly is anchored inthe posterior chamber of the eye, the method comprising the steps of: a.introducing the first haptic portion, which comprises said first anchorportion including a plurality of teeth projecting therefrom, into theposterior chamber of the eye until said teeth are anchored in thescleral wall at a desired location; and b. moving the second hapticportion, which comprises a second anchor portion including a pluralityof teeth projecting therefrom, until said teeth are anchored in thescleral wall on the opposite side of the lens from the first anchorportion.
 20. The method of claim 19, wherein the haptic portions furthercomprise a plate with first and second telescoping members, the firstmember extending outwardly from the outer periphery of the lens in afirst direction and the second member extending from the outer peripheryof the lens in a direction opposite the first member, and the step ofmoving the second haptic portion further comprises extending the secondtelescoping member.
 21. The method of claim 19, wherein the lensstructure further comprises a resilient lens body.
 22. The method ofclaim 19, wherein the lens structure further comprises a resilient lensbody and a rigid lens body, whereby the resilient lens is positionedbetween the rigid lens body and the haptics element after the lensassembly is anchored in place.
 23. The method of claim 19, wherein thelens structure further comprises a resilient lens body and a rigidpiston member with a cylindrical cavity formed therethrough, whereby theresilient lens body is positioned between the rigid piston member andthe haptics element after the lens assembly is anchored in place.
 24. Anintraocular lens assembly for implantation in the posterior chamber ofan eye, the lens assembly having an optical axis that corresponds withthe visual axis of a human eye, the posterior chamber including aciliary sulcus, the assembly comprising a substantially rigid hapticselement comprising first and second haptic portions with outermostportions, comprising first and second anchor portions with a pluralityof teeth rigid enough to penetrate the scleral wall, which, when theteeth are anchored in the scleral wall, define a plane that intersectsthe visual axis of the eye, said haptics element securing saidintraocular lens assembly within the posterior chamber, and a lensstructure that includes at least a lens body located at least partiallyalong the visual axis when the lens assembly is anchored in theposterior chamber of the eye.
 25. The lens assembly of claim 24, whereinthe haptic portions further comprise a plate with first and secondtelescoping members, the first member extending outwardly from the outerperiphery of the lens in a first direction and the second memberextending from the outer periphery of the lens in a direction oppositethe first member, and the step of moving the second haptic portionfurther comprises extending the second telescoping member.
 26. The lensassembly of claim 24, wherein the lens structure further comprises aresilient lens body positioned between the haptics element and thecollapsed natural lens capsule after the lens assembly is anchored inplace.
 27. The lens assembly of claim 24, wherein the lens structurefurther comprises a resilient lens body and a rigid lens body, wherebythe resilient lens is positioned between the rigid lens body and thehaptics element after the lens assembly is anchored in place.
 28. Thelens assembly of claim 24, wherein the lens structure further comprisesa resilient lens body and a rigid piston member with a cylindricalcavity formed therethrough, whereby the resilient lens body ispositioned between the rigid piston member and the haptics element afterthe lens assembly is anchored in place.